Floating solar photovoltaic array with on-board energy management system for controlling and powering inflatable support pontoons, water quality, air compression and mooring devices

ABSTRACT

A floating solar photovoltaic array having an energy management power control system configured to send power clipped by an inverter to the at least one powered accessory device which can be an aerator, a diffuser, a sub-surface agitator, a sub-surface water circulator, a sub-surface positioning/mooring system, a water quality sensor; a panel washer, or a bird removal system. The array has inflatable pontoons and an air manifold system which is powered by the solar photovoltaic modules can be used to adjust the angle of inclination of the solar photovoltaic modules to the sun. The powered accessories can also be powered by unclipped power or on-shore power or combinations thereof which can be controllably adjusted by the energy management control system over time.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication Ser. No. 63/171,981, entitled A System For FacileIntegration Of Water Quality Control Devices Into Floating SolarSystems, filed Apr. 7, 2021; and to U.S. Provisional Patent ApplicationSer. No. 63/179,925, entitled A Module Float Design Feature That ReducesExternal Hardware Requirements For Mounting Modules To Structures InFloating Solar Systems, filed Apr. 26, 2021, the entire disclosures ofwhich are incorporated herein by reference in their entireties for allpurposes.

TECHNICAL FILED

The present system relates to floating solar photovoltaic (PV) arrays.

BACKGROUND OF THE INVENTION

Currently, one challenge that can affects the adoption of floating solarPV arrays is that they have unknown impacts to water quality. Whilefloating solar arrays have been claimed to provide passive benefits totheir host water bodies, including reduced evaporation and algae growth,there is still a large gap in knowledge about the extent of impact. Whatis desired is a floating solar PV array that includes systems thatremediate or improve water quality. Ideally, such a system would alsomeasure and regulate important water quality parameters. As will beshown, the present system can achieve these objectives.

Secondly, although water remediation systems including aerators anddiffusers have been used in conjunction with floating solar arrays inthe past, powering these remediation systems is expensive and presentssome challenges. The standard method for running these remediationsystems is simply to run a power line or compressed air supply line fromthe shore out to the solar array as the power or air source for thesewater remediation devices. In this configuration, the floating solar PVarray and water accessory devices are decoupled from and electrical andcontrols standpoint. What is instead desired is a system that can usethe power that is already being generated by the solar PV array to powerthese various water quality remediation devices. This desired systemthat integrates the floating solar PV array and water accessories canreduce the cost of water management for water body operators. Since thepower generated by the array changes over the course of the day (and isbasically not available at night), an ideal solution would also balancepower inputs from the array itself and from the on-shore grid to operatethe various water quality remediation devices at the specific times (andin the specific amounts) that they are needed. In addition, an idealsystem would also use the power generated by the PV modules that isnormally clipped by the inverter to power these various water qualityremediation devices. This use of inverter-clipped power has not beenachieved in the past. Ideally, such an on-board power management systemwould use the inverter-clipped power, but also be able to supplementthis power with non-clipped power or even on-shore power as required torun the various water quality remediation devices (and other devices) atdifferent times and during changing environmental and power generatingconditions. As will be shown, the present system addresses thesechallenges and overcomes them.

Another one of the biggest challenges with floating solar PV arrays ingeneral is their high costs (as compared to land-based solar PV arrays).This is due to several factors. First, floating components tend to bequite specialized for use on the water, and are therefore somewhatexpensive. Second, it can be expensive to ship these specializedcomponents to the body of water on which they will be assembled anddeployed. Third, additional costs are also incurred in the actualassembly of floating solar arrays, which are more challenging to buildthan land-based arrays as standard installation practices are stillbeing defined. Finally, floating solar arrays are also more expensive tomaintain as the operator needs to come out on the water to access thearray.

What is instead desired is a floating solar PV array that offers reducedcosts as compared to existing floating systems. First, it would bedesirable to reduce the costs of the various components themselves. Assuch, it would also be desirable to reduce the size and weight of thesecomponents (to reduce their shipping costs). Finally, it would bedesirable to provide a floating solar PV array that is fast and easy toassemble (such that assembly times and associated labor costs arereduced). As will be shown herein, the present system achieves theseobjectives by providing an inexpensive and lightweight system. Thepresent system can be compacted when shipped and assembled relativelyeasily and inexpensively. In addition, the present system usesrelatively fewer components than are normally found in floating solar PVarrays to support the PV modules.

Another common problem with floating solar PV arrays is that it can bedifficult to access all of their components after they have beenassembled and deployed out on the body of water. As will be shown, thepresent system has design features that permit easy operator access tothe various parts of the array while the array is floating on the bodyof water.

Another problem with floating solar PV arrays is that they typically donot move their PV module orientation to track the movement of the sun.As will be shown, the present system includes optional mechanisms thatcan move the PV modules both by adjusting their angle of tilt to thehorizon and also optionally by rotating the array on the water's surfaceto track the movement of the sun. As such, multi-axes tracking of thesun can be achieved using the present system.

SUMMARY OF THE INVENTION

In preferred aspects, the present system includes a system for poweringan accessory device with power generated on a floating solarphotovoltaic (PV) array, comprising: a plurality of PV modules; aplurality of floating pontoons for supporting the PV modules above thewater; an inverter for receiving DC power from the PV modules andconverting the DC power to AC power, wherein the inverter has an ACpower limit such that any power received above the AC Power limit wouldbe clipped by the inverter; at least one powered accessory device; apower line running from the floating solar array to an on-shore grid;and an energy management power control system.

The energy management control system is configured to send power to atleast one powered accessory device (which preferably includes a waterremediation device, air compressor, mooring system or other device). Thepower sent to this accessory device includes power that has been clippedby the inverter. The advantage of this approach (i.e.: usinginverter-clipped power to power the accessory device) is that it powersthe accessory device with power that would otherwise be lost and notsent to shore. In optional aspects, however, the power sent to theaccessory device can also include power that has not been clipped by theinverter. This approach includes sending power to the accessory devicethat could otherwise have been sent from the array directly to theon-shore power grid. This approach could be beneficial for short periodsof time when it is necessary to have the powered accessory device turnedon (for example, during extended water remediation), but when theinverter-clipped power is not sufficient all by itself to power thewater remediation device. The present energy management control systemthus balances (and varies) these two different sources of power overtime. For example, some of the non-clipped power could be sent from thePV modules to keep an aerator on late in the day when the array's poweroutput is lower (such that inverter-clipped power alone would not beable to keep the aerator running). In optional preferred aspects, thepresent energy management control system also is configured to receivepower through a power line running from the floating solar array to theon-shore grid to send power to at least one powered accessory device.Again, this third source of power can be balanced and controlled overtime. As a result, the present energy management power control system isconfigured to send power to at least one powered accessory device byadjustably changing the amounts of power received from each of thefollowing power sources over a period of time: (i) power received fromthe PV modules that has been clipped by the inverter, (ii) powerreceived from the PV modules that has not been clipped by the inverter,and (iii) power received from the on-shore grid. True, three-way powerbalancing can be achieved.

In preferred aspects, the powered water remediation accessory device isa water quality device, being one or more of an aerator, a diffuser, asub-surface agitator, a sub-surface water circulator, or a water qualitysensor. In other aspects, the powered accessory device is an aircompressor for inflating the plurality of pontoons. In yet otheraspects, the powered accessory device is a positional mooring device, apanel washer, or a bird removal system.

In various aspects, the present floating solar PV array comprises: (a) aplurality of inflatable upper support pontoons with upper mountinghardware thereon; (b) a plurality of lower support pontoons with lowermounting hardware thereon; and (c) a plurality of solar photovoltaicmodules, wherein each solar photovoltaic module has an upper end that isconnected to the mounting hardware on one of the inflatable uppersupport pontoons and a lower end that is connected to the mountinghardware on one of the lower support pontoons. The mounting hardware onthe inflatable upper support pontoons is higher (i.e.: farther from thewater) than the mounting hardware on the lower support pontoons tothereby hold each of the solar photovoltaic modules at an inclined angleto the water below. In addition, the mounting hardware of the presentsystem involves a minimum of parts. In one embodiment, only hooks ormodule mounting feet are used to attach the ends of the PV modules toeach of the upper and lower support pontoons.

The present system also comprises an air manifold system. As describedherein, the air manifold system can include any air source. As such, theair source can include an air compressor or an air tank or a combinationthereof. Pneumatic tubing is provided to connect the air source to eachof the plurality of inflatable support pontoons. Pressure sensors arealso preferably provided for determining air pressures in the inflatablesupport pontoons. An air manifold control system controls the airpressures in the inflatable support pontoons. Preferably, the entire airmanifold system is powered by the photovoltaic modules in the solarphotovoltaic array. As such, the present system can be fullyself-contained in terms of sensing and maintaining its internal airpressures. This offers numerous benefits. For example, should airpressures fall in any of the support pontoons, the present system isable to detect the pressure drop and provide correction and re-inflatethe support pontoons to within desired pressure ranges. A particularlyunique advantage of the present self-contained pontoon inflation controlsystem is that the pressures in the upper support pontoons can bechanged to adjust the incident angle of the PV modules towards the sun.In addition, the upper support pontoons can be partially deflated to“stow” the system for safety reasons if the system is struck by adverseweather conditions.

An important advantage of the present system of upper and lower pontoonssupporting the solar PV modules is that they substantially reduce thephysical shipping volume of components in the array. Specifically, sincethe upper pontoons are inflatable, they are lightweight and can ideallybe collapsed and packed tightly together during shipping. In variousaspects, the lower pontoons may be inflatable as well, further reducingthe shipping size and weight of the present system. In preferredembodiments, the upper support pontoons may simply be inflatablecylinders with mounting hardware attached directly thereto.

In preferred aspects, the inclined angle of each of the solarphotovoltaic modules can be adjusted by adjusting an inflation level inthe inflatable upper support pontoons. This advantageously provides theability to track the sun's movement over the course of the day tooptimize power generation in the array.

In preferred embodiments, the lower support pontoons may have aflattened top surface that functions as a walkway that supports theweight of an operator. This flattened top surface advantageously permitsease of access during both initial assembly on the water and for systemmaintenance thereafter.

In preferred aspects, the upper and lower support pontoons hold each ofthe solar PV modules above the water such that the center portion ofeach solar PV module is suspended directly above the water with nomechanical structures positioned directly underneath. As such, the solarPV modules are each simply suspended above the water with the onlymechanical connection between any of the inflatable upper supportpontoons and any of the lower support pontoons being through the solarphotovoltaic module itself. The advantage of this design is that itsubstantially reduces the total amount of system support hardware. Infact, the mounting hardware on each of the inflatable upper supportpontoons can simply include a U-ring connector thermally welded oradhesively connected to the inflatable upper support pontoon. Incontrast, existing floating solar arrays tend to require many morefastening components.

In preferred aspects, the present system also includes a poweredaccessory which may be an aerator, a diffuser, a sub-surface agitator, asub-surface water circulator, a sub-surface positioning/mooring system,a water quality sensor; a PV module panel washer, or even or a birdremoval system, or some combination thereof. The advantage of aerators,diffusers, sub-surface agitators, sub-surface water circulators, andwater quality sensors is that they can be used to improve water quality.The advantage of a sub-surface mooring system is that it can be used tokeep the array at a preferred location, and to optionally rotate thearray to track the movement of the sun across the sky. The advantages ofpanel washing or bird-removal systems are that they can be used tomaximize power generation from the array. In all cases, these differentpowered accessories are preferably powered using inverter-clipped powerfrom the PV modules in the array itself. As stated above, these variousaccessories may be completely powered by the array, or the array maypower these accessories some of the time. The present energy managementcontrol system determines which power source(s) are used at which timesand in what amounts. The energy management control system also adjuststhese various energy sources over time under changing conditions. Assuch, the energy management control system can supply power generated bythe PV modules in the array (including both inverter-clipped power andpower that has not been clipped by the inverter) together with optionalpower sources including an on-board battery, or a power connection lineto the on-shore grid, or both. In most preferred aspects, and duringmost of the time, the powered accessory can advantageously be powered bythe output from the solar PV modules that has been clipped by aninverter. As such, the accessories can be powered from power that wouldotherwise be lost and not sent to shore.

A further advantage of the present system is that there is a widevariety of different configurations or layouts in which the system canbe deployed. For example, the individual solar PV modules can be laidout in rows with all of the solar PV modules facing south.Alternatively, the solar PV modules can be laid out with alternatingrows angled east and west. The individual solar PV modules can all belaid out in portrait orientation. Alternatively, however, the individualsolar PV modules can all be laid out in landscape orientation.

In various preferred embodiments, the present solar PV array can havedifferent numbers of upper and lower support pontoons in differentconfigurations. For example, in various arrangements, each of the solarPV modules can have their own dedicated upper support pontoon.Alternatively, two or more solar PV modules can share the same uppersupport pontoon. In addition, although several solar PV modules can bemounted to the same lower support pontoon, the width of the presentarray can be extended by linking together more than one lower supportpontoon.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the present solarphotovoltaic array.

FIG. 2A is a side elevation view of a section of an embodiment of thepresent solar photovoltaic array in a south-facing orientation.

FIG. 2B is a side elevation view of a section of an embodiment of thepresent solar photovoltaic array in an east-west south-facingorientation.

FIG. 3 is a simplified schematic perspective view of an arraycorresponding to FIG. 2A.

FIG. 4A is a side elevation view of an embodiment of the present solarPV array showing optional powered accessories including a surfaceaerator, a diffuser, sub-surface agitator, and a sub-surface watercirculator.

FIG. 4B is a side elevation view of an embodiment of the present solarPV array showing an optional sub-surface mooring system.

FIG. 4C is a perspective view of the solar PV array of FIG. 1, showing apanel washer and a bird removal system.

FIG. 5 is an exemplary graph of array power generated over time showingthe portion of inverter-clipped power directed to the powered accessory.

FIG. 6A is an exemplary graph showing inverter-clipped power sent to apowered accessory over a period of time.

FIG. 6B is an exemplary graph showing the portions of bothinverter-clipped power and power that has not been clipped by theinverter being sent to the powered accessory (or accessories) over aperiod of time.

FIG. 6C is an exemplary graph showing the portions of inverter-clippedpower, non-inverter-clipped power and shore-received power being sent tothe powered accessory (or accessories) over a period of time.

FIG. 7A is an exemplary graph showing various sources of power beinggenerated by the solar PV array over a continuous 24 hour period.

FIG. 7B shows the power being sent to the powered accessory (oraccessories) corresponding to FIG. 7A during the continuous 24 hourperiod.

FIG. 8A is an exemplary graph showing various sources of power beinggenerated by the solar PV array over a specific on-demand period oftime.

FIG. 8B shows the power being sent to the powered accessory (oraccessories) corresponding to FIG. 8A during on-demand operation of thepowered accessory (or accessories).

FIG. 9A is a schematic of powering the powered accessories using a DCbus.

FIG. 9B is a schematic of powering the powered accessories using an ACbus.

FIG. 9C is a schematic of powering the powered accessories using anelectrically isolated system.

FIG. 10A is a top plan view of the present solar PV array laid out withthe PV modules in a portrait, south facing orientation, with the PVmodules each having a dedicated upper support pontoon.

FIG. 10B is a top plan view of the present solar PV array laid out withthe PV modules in a portrait, south facing orientation, with PV modulessharing upper support pontoons.

FIG. 10C is a top plan view of the present solar PV array laid out withthe PV modules in a landscape, south facing orientation.

FIG. 10D is a top plan view of the present solar PV array laid out withthe PV modules in a portrait, east-west facing orientation, with the PVmodules each having a dedicated upper support pontoon.

FIG. 10E is a top plan view of the present solar PV array laid out withthe PV modules in a portrait, east-west facing orientation, with the PVmodules sharing upper support pontoons.

FIG. 11A is a bottom plan schematic view of an embodiment of the presentfloating solar PV array showing a sub-surface mooring/positioningsystem.

FIG. 11B is a side elevation view corresponding to FIG. 11A.

FIG. 12A shows top and side view of a first system for attaching twolower support pontoons together.

FIG. 12B shows top and side view of a second system for attaching twolower support pontoons together.

FIG. 13 is a view similar to FIG. 3, showing one preferred embodiment ofthe present floating solar PV array.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 4C show various embodiments of the present floating solarphotovoltaic array 10, and its system of powering various accessorydevices. In its various aspects, as seen in FIG. 1, the systemcomprises: a plurality of PV modules 40; a plurality of floatingpontoons 30 for supporting PV modules 40 above the water; an inverter 50or 262 for receiving DC power from PV modules 40 and converting the DCpower to AC power. As will be explained, inverter 262 has an AC powerlimit such that any power received above the AC Power limit would beclipped by the inverter. Also included are at least one poweredaccessory device 80; a power 260 line running from the floating solararray 10 to an on-shore grid; and an energy management power controlsystem 400 configured to send power that has been clipped by theinverter to the at least one powered accessory device 80.

In preferred aspects, energy management power control system 400 isfurther configured to send power that has not been clipped by theinverter to the at least one powered accessory device. In still furtheraspects, energy management power control system 400 is furtherconfigured to receive power through the power line 260 running from thefloating solar array to the on-shore grid to send power to the at leastone powered accessory device 80. As such, energy management powercontrol system 400 can be configured to send power to the at least onepowered accessory device 80 by adjustably changing the amounts of powerreceived from each of the following power sources over a period of time:(i) power received from the PV modules that has been clipped by theinverter, (ii) power received from the PV modules that has not beenclipped by the inverter, and (iii) power received from the on-shoregrid.

In various preferred aspects, powered accessory device 80 may be a waterquality device including any one or more of the surface aerator 200, thedredger 201, the air compressor 202, the ozone treatment device 203 orthe water sensor 204 illustrated in FIG. 1; or the aerator 200, diffuser210, sub-surface agitator 220, or sub-surface water circulator 230illustrated in FIG. 4A; the mooring/positional system 250 illustrated inFIG. 4B or the panel washer 270 or bird removal system 280 illustratedin FIG. 4C. As will be further explained, when the powered accessory 80is air compressor 202, the air compressor can be used for inflating theplurality of pontoons. In optional embodiments, the powered accessorycould also include debris collectors, UV treatment equipment,desalination equipment, or electrolyzers.

Turning next to FIGS. 2A to 3, various exemplary embodiments of thepresent array 10 are seen. It is to be understood that for clarity ofunderstanding these figures are only simplified illustrations, and thatnot all structural components are illustrated.

FIG. 2A shows module 40 facing in a southward direction. In commercialembodiments, a plurality of the systems illustrated in FIG. 2A arepositioned side by side (for example as seen in FIG. 3). FIG. 2B showsalternating rows of modules 40 facing in either an east or westdirection. As seen in FIGS. 2A and 3, array 10 comprises: a plurality ofinflatable upper support pontoons 20 with upper mounting hardware/mounts22 thereon; a plurality of lower support pontoons 30 with lower mountinghardware/mounts 32 thereon; and a plurality of solar photovoltaicmodules 40 mounted therebetween. As seen in FIG. 2B, two PV modules 40may share the same upper support pontoon 20.

Each solar photovoltaic module 40 has an upper end 41 that is connectedto the mounting hardware/mounts 22 on one of the inflatable uppersupport pontoons 20 and a lower end 43 that is connected to the mountinghardware/mounts 32 on one of the lower support pontoons 30. As can beseen, the mounting hardware/mounts 22 on inflatable upper supportpontoon 20 is higher (i.e.: farther above the water) than the mountinghardware/mounts 32 on lower support pontoon 30. This preferred designholds each of the solar photovoltaic modules 40 at an inclined angle, asshown. In other embodiments, the mounting hardware 22 on each of theinflatable upper support pontoons 20 includes a U-ring connectorthermally welded or adhesively connected to the inflatable upper supportpontoon.

In preferred aspects, upper support pontoon 20 may be an inflatablecylindrical tube made of materials including, but not limited to, HighDensity Polyethylene (HDPE), Thermoplastic Olefin (TPO), PolyvinyclChloride (PVC), Ethylene tetrafluoroethylene (ETFE), or a PVC-coatedfabric. Preferably, upper support pontoons 20 have a thickness ofbetween 50 um to 25 mm, or more preferably between 0.5 and 2.5 mm.

Lower support pontoons 30 may be made of similar materials and may alsobe inflatable. Also in preferred aspects, the lower support pontoons 30have a flattened top surface 31 that can function as a walkway foroperators to gain access to the PV modules. In optional aspects, a wiremanagement chamber can be positioned on or in the lower support pontoons30.

As explained above, the present array 10 also includes an air manifoldsystem 100 (shown schematically in FIG. 3). System 100 preferablycomprises an air compressor 202 (See FIG. 1) (or any other air sourceincluding an air tank), and pneumatic tubing 140 (see also FIGS. 10A to10E) connecting air compressor 202 to each of the plurality ofinflatable upper support pontoons 20. Pressure sensors 150 can beincluded for determining air pressures in each of the inflatable uppersupport pontoons 20. Lastly, an air manifold control system 160 can beused for measuring the output of pressure sensors 150 and controllingthe air pressures in each of the inflatable upper support pontoons 20.Most preferably, air manifold system 100 is completely (or at leastpartially) powered by the photovoltaic modules 40 in the solarphotovoltaic array.

In preferred aspects, the inclined angle of each of the solarphotovoltaic modules 40 can be adjusted simply by adjusting an inflationlevel in one of the inflatable upper support pontoons 20. Specifically,as an upper support pontoon 20 is inflated, the top end 41 of a solar PVmodule 40 will be raised, thereby placing PV module 40 into a somewhatmore vertical orientation. Conversely, deflating upper support pontoon20 will place the PCV module 40 into a somewhat more horizontalorientation. Therefore, by changing the inflation pressures within uppersupport pontoons 20 over the course of a day, the angle of tile of thePV modules can be made to better track the motion of the sun.

As can be appreciated, the present floating mounting system usessubstantially fewer components than traditional floating solar PVarrays. Instead, with the present system, so few components are requiredthat the center portion of each solar photovoltaic module 40 can bepositioned directly above water with no mechanical structure positioneddirectly thereunder (as seen in FIGS. 2A and 2B). As such, the onlymechanical connection between any of the inflatable upper supportpontoons and any of the lower support pontoons is through one of thesolar photovoltaic modules.

Next, FIG. 4A illustrates the present solar PV array 10 showing avariety of optional powered accessories (e.g.: devices 80 in FIG. 1)that may be included therewith. Most preferably, these various poweredaccessories are powered by the PV modules 40 in the solar photovoltaicarray. It is to be understood, however, that these powered accessoriescan be powered from a battery on the array (which may be recharged bythe PV modules). As such, the powered accessory can be powered directlyfrom the PV modules during the day and through the battery during thenight (after the battery has been re-charged by the PV modules duringthe day).

In various aspects, the powered accessories can optionally include anaerator 200, a diffuser 210, sub-surface agitator 220, a sub-surfacewater circulator 230, and a water quality sensor (204 in FIG. 1). It isto be understood that the present system can include any number orcombination of these accessories. Placing large, floating solar arraysonto bodies of water has the advantage of not requiring large amounts ofterrestrial real estate for array deployment. Unfortunately, covering acomparatively large body of water with a floating solar array can haveundesirable effects. For example, stratification of the water can be aproblem. Floating solar arrays also interfere with natural wave motionand partially block the sun from reaching the water, thereby darkeningthe water below the array.

Accessories 200, 210, 220 and 230 (and 203 in FIG. 1) can be used toremediate or improve water quality, and water quality sensor (204 inFIG. 1) can be used for measuring water quality. For example, aerator200 can be a floating surface fountain as illustrated that sprays waterupwards. Diffuser 210 can be a bottom resting device that releasesbubbles of air (i.e.: air is pumped air down in a tube from above thearray and released underwater it so that it bubbles upwards). Bothaerator 200 and diffuser 210 assist in aerating the water. Sub-surfaceagitator 230 can be a propeller/turbine device mounted to the undersideof the array that stirs the water under array 10. Sub-surface watercirculator 230 can be a bottom mounted propeller/turbine device thatstirs the water under array 10. These powered accessories help repairstratified water bodies, prevent algae blooms, and support desired floraand fauna.

Ideally, accessories 200, 210, 220, 230 and 203 can be powered by PVmodules 40, thereby permitting their operation during the daytime (whenpower is being generated by the array). Since accessories 200, 210, 220,230 and 203 typically do not need to be operating 24 hours/day toprovide benefits, it is possible to operate these accessories solelyrelying upon power generated from the PV modules 40. This provides afully self-contained water quality remediation system. When waterquality remediation devices such as these are integrated into thepresent solar array, installation costs are minimal. In addition,another advantage of using these powered accessories/water qualityremediation devices is that it reduces the future costs of maintenanceprograms to reduce pond scum and toxic gasses. However, although thesevarious devices may be powered solely by array 10, it is to beunderstood that the present system also encompasses variations withaccessories 200, 210, 220 and 230 powered by PV modules 40, an on-boardbattery, a power line 260 running to shore or any combination thereof.

FIG. 4B is a side elevation view of the present solar PV array showingan optional sub-surface mooring/positioning system 250. Sub-surfacemooring system 250 comprises a plurality of different propeller/turbinesthat move array 10 to a desired location (or keep array 10 at a desiredlocation on the body of water). Although sub-surface positioning system250 may be powered by PV modules 40, it is to be understood that itspower may also be supplemented by an on-board battery or by a power line260 running to shore (to power sub-surface positioning system 250 duringthe night). FIGS. 11A and 11B show another preferred embodiment ofmooring system 250, as follows. In FIG. 11A, a plurality of separateturbine/propeller systems 251 and 252. Propellers 251 point outwardlyfrom the bottom of array 10. Conversely, propellers 252 point inwardlyunder the bottom of array 10. By selectively turning on and off any ofthese propellers/turbines 251 and 252, it is possible to move the array10 in any desired direction. This includes both moving the array to adesired location and keeping it there. For example, on a calm day,propellers/turbines 251 and 252 may be turned off. However, on a windyday, those propellers/turbines 251 and 252 that are pointing in adirection opposite to the wind may be turned on to keep the array in adesired position. Propellers/turbines 251 and 252 can also beselectively turned on and off to rotate array 10 on the body of watersuch that PV modules 40 can track the movement of the sun. The presentsystem encompasses embodiments in which propellers/turbines 251 and 252are individually steerable and embodiments where propellers/turbines 251and 252 are operated at different intensities (for example, with astrong horizontal “pushback” on a windy day to keep the array at adesired location on the body of water, together with a smallerrotational “push” causing the array to rotate to track the sun over thecourse of the day).

As seen in FIG. 11B, propeller/turbines 251A in system 250 can be angledslightly downwards to further assist in keeping array 10 buoyant (ascompared to more horizontal directed propeller/turbine 251B). In variousaspects, the present system also includes a plurality of mooring cablesconnected to at least one of the plurality of inflatable upper supportpontoons 20 or lower support pontoons 20 for mooring the array at adesired location on a body of water.

FIG. 4C is a perspective view of the present solar PV array 10 showingan optional panel washer 270 and an optional bird removal system 280.Panel washer system 270 may simply comprise a sprayer 275 than can bedirected to suck up water from below the array (with submersible pump276) and spray the water onto the surfaces of PV modules 40 toperiodically clean the modules. Sprayer 275 can be automaticallycontrolled to point in various directions to cover the surfaces of thedifferent PV modules. The various cleaning routines can be programmedinto the control system such that sprayer 275 sprays the surfaces of PVmodules 40 one after another. Optional bird removal system 280 canfunction similar to panel washer 270. Specifically, bird removal system280 suck up water from below the array and spray the water onto thesurfaces of PV modules 40. However, the modules 40 are only sprayed whencamera/motion sensor 285 detects a bird sitting on one of the PV modules40. When a bird is viewed sitting on one of the PV modules, the sprayer275 is aimed at the bird.

FIG. 5 is an exemplary graph of array power generated over time showingthe portion of inverter-clipped power directed to the powered accessory.Specifically, over a 24 hour period, power output from PV modules 40peaks mid-day, and is zero overnight. However, in this example, themaximum power the inverter is able to send to the grid (via power line260 to shore in FIG. 4A or 4B) is 2500 KW. Accordingly, the power inregion 500 can be sent to the on-shore grid. However, the power inregion 520 will be “clipped” by the inverter and cannot be sent toshore. Accordingly, in accordance with the present energy managementpower control system 400, the power in region 520 is instead sentdirectly to power an accessory 80 such as aerator 200. Accordingly, theaerator is operated between about 8 am and 3 pm. Should it be desirableto operate an accessory 80 at extended periods of time, energymanagement power control system 400 can use different power balancingapproaches as explained in FIGS. 6A to 8B as follows.

FIG. 6A is an exemplary graph showing inverter-clipped power 520 sent toa powered accessory 80 over a period of time. In this illustration,accessory 80 will only be operated during daylight hours wheninverter-clipped power 520 is available.

FIG. 6B is an exemplary graph showing the portions of bothinverter-clipped power 520 and power 500 that has not been clipped bythe inverter being sent to the powered accessory (or accessories) 80over a period of time. In this illustration, non-clipped power 500 isused at the end of the day to power accessory 80 when inverter-clippedpower has tapered off.

Finally, FIG. 6C is an exemplary graph showing the portions ofinverter-clipped power 520, non-inverter-clipped power 500 andshore-received power 540 all being sent to the powered accessory (oraccessories) 80 over a period of time. This specific illustration istaken over a period of a full year and shows the situation where somepower from the grid (i.e.: power 540) is used to power accessory 80throughout the course of the year.

FIG. 7A is an exemplary graph showing various sources of power beinggenerated by the solar PV array over a continuous 24 hour period. FIG.7B shows the power being sent to the powered accessory (or accessories)corresponding to FIG. 7A during the continuous 24 hour period.Specifically, inverter-clipped power 520 is only sent to accessory 80when such power is available (between about 6 am and 12 pm and 1 pm to 6pm). Accordingly, power 500 (which has not been clipped by the inverter)will also be sent to accessory 80 from about Gam to 6 pm such that theaccessory has sufficient power for its operation (i.e.: such that thecombined power regions 500 and 520 total the necessary power to run thedevice—identified as “WT Load” in FIG. 7B). Before Gam and after 6 pm,the PV modules 40 won't be generating any power. Thus, power 540 will bedrawing directly from the grid to keep the accessories running. As canbe seen, the relative contributions of power regions/sources 500/520/540will change over time. Early in the morning as the day starts, gridpower 540 is phased out as non-clipped power 500 comes online. Bymid-day, clipped power 520 starts to come online (as the PV modules 40exceed the “PV AC Limit” seen in FIG. 7A), and the amount of non-clippedpower 500 can be reduced. Later in the day, clipped power 520 starts todecrease until all power is supplied by non-clipped power source 500(between about 5 μm and 6 pm). Finally, as non-clipped power source 500starts to fall off, then grid power 540 will begin to take up the slackand will be the final sole power source overnight. Region 600 representsthe power that array 10 supplies to the on-shore grid over the course ofthe day.

FIGS. 8A and 8B are similar to FIGS. 7A and 7B, however, FIGS. 8A and 8Bdeal with the situation where the powered accessory 80 need only beoperated between about 10 am and 9 pm. Specifically, at around 10 am,power is supplied to the powered accessory from regions/sources 500 and520. As can be seen, the relative proportions of these two amounts willvary somewhat over the course of the day. After about 6 pm, the poweredaccessory will rely solely upon grid-supplied power 540. At about 9 pm,the device 80 will be turned off and not turned on again until about 10am the next morning. Power region 521 is “lost power” that has beenclipped by the inverter but is not required to power accessory 80 atthat particular time.

FIGS. 9A to 9C show different schematics of powering the poweredaccessories. Specifically, FIG. 9A shows powering using a DC bus; FIG.9B shows powering using an AC bus; and FIG. 9C shows powering using anelectrically isolated system.

In FIG. 9A, an on-shore inverter (262 in FIG. 1) converts DC output fromthe solar photovoltaic modules 40 into AC power, and a DC bus 300 sendsthe DC power to the on-shore inverter. Advantages of using DC Bus 300include lower DC ohmic losses, and the ability to use clipped power 520with a constrained AC connection more easily. In addition, voltage droopcontrol can be used.

In FIG. 9B, a dedicated on-board inverter 55 converts DC output fromeach of the solar photovoltaic modules into AC power, and an AC bus 320is connected to the inverter for sending AC power to shore. Advantagesof using AC bus 300 include the fact that any type of solar inverter 55can be used, and off-the-shelf VFDs and AC motor drives can be used topower the aerators.

Lastly, in FIG. 9C, an advantage of an electrically isolated system isthat, again, any type of solar inverter can be used.

Next, FIGS. 10A to 10E show various layouts of the PV modules 40 usingthe present floating mounting system. Specifically, FIG. 10A (whichcorresponds to FIGS. 2A and 3) shows PV modules 40 in a portrait, southfacing orientation. As can be seen, each PV module 40 has its owndedicated upper support pontoon 20. FIG. 10B (which also corresponds toFIGS. 2A and 3) also shows the PV modules in a portrait, south facingorientation, but two PV modules 40 are sharing each upper supportpontoon 20. FIG. 10C (which also corresponds to FIGS. 2A and 3) showsthe PV modules 40 laid out in a landscape, south facing orientation.FIG. 10D (which corresponds to FIG. 2B) shows the PV modules 40 mountedin portrait, but laid out in in an east-west facing orientation.Specifically, a two rows of upper support pontoons 20 are next to oneanother. For a large array, two rows of lower support pontoons 30 wouldbe positioned next to one another. As seen in FIG. 10D, each of the PVmodules 40 have their own dedicated upper support pontoon 20. Lastly,FIG. 10E (which corresponds to FIG. 2B) shows PV modules 40 laid out ina portrait, east-west facing orientation, with the individual PV modules40 sharing upper support pontoons 20. As can be appreciated, a widevariety of different array configurations are possible with the presentsystem (depending upon where the successive rows of pontoons 20 and 30are positioned, and whether the PV modules 40 are positioned in portraitor landscape).

Finally, FIGS. 12A and 12B show various systems for attaching two lowersupport pontoons 30 together. Specifically, FIG. 12A shows top and sideviews of a system for attaching pontoons 30 together using elasticconnectors 35. FIG. 12B shows top and side views of a system forattaching pontoons 30 together using mechanical plates 37.

What is claimed is:
 1. A system for powering an accessory device withpower generated on a floating solar photovoltaic (PV) array, comprising:(a) a plurality of PV modules; (b) a plurality of floating pontoons forsupporting the PV modules above the water; (c) an inverter for receivingDC power from the PV modules and converting the DC power to AC power,wherein the inverter has an AC power limit such that any power receivedabove the AC Power limit would be clipped by the inverter; (d) at leastone powered accessory device; (e) a power line running from the floatingsolar array to an on-shore grid; and (f) an energy management powercontrol system configured to send power that has been clipped by theinverter to the at least one powered accessory device.
 2. The system ofclaim 1, wherein the energy management power control system is furtherconfigured to send power that has not been clipped by the inverter tothe at least one powered accessory device.
 3. The system of claim 1,wherein the energy management power control system is further configuredto receive power through the power line running from the floating solararray to the on-shore grid to send power to the at least one poweredaccessory device.
 4. The system of claim 1, wherein the energymanagement power control system is configured to send power to the atleast one powered accessory device by adjustably changing the amounts ofpower received from each of the following power sources over a period oftime: power received from the PV modules that has been clipped by theinverter, power received from the PV modules that has not been clippedby the inverter, and power received from the on-shore grid.
 5. Thesystem of claim 1, wherein the powered accessory device is a waterquality device, being one or more of an aerator, a diffuser, asub-surface agitator, a sub-surface water circulator, or a water qualitysensor.
 6. The system of claim 1, wherein the powered accessory deviceis an air compressor for inflating the plurality of pontoons.
 7. Thesystem of claim 1, wherein the powered accessory device is a positionalmooring device.
 8. The system of claim 1, wherein the powered accessorydevice is a panel washer, or a bird removal system.
 9. The system ofclaim 1, wherein the plurality of floating pontoons comprise: aplurality of inflatable upper support pontoons with upper mountinghardware thereon and a plurality of inflatable lower support pontoonswith lower mounting hardware thereon, wherein each solar photovoltaicmodule has an upper end that is connected to the mounting hardware onone of the inflatable upper support pontoons and a lower end that isconnected to the mounting hardware on one of the inflatable lowersupport pontoons, and wherein the mounting hardware on the inflatableupper support pontoons is higher than the mounting hardware on theinflatable lower support pontoons to thereby hold each of the solarphotovoltaic modules at an inclined angle.
 10. The system of claim 9,further comprising: an air manifold system, comprising: at least one ofan air source or an air compressor, and pneumatic tubing connecting theair source or air compressor to each of the plurality of inflatablesupport pontoons; pressure sensors for determining air pressures in theinflatable support pontoons; and an air manifold control system forcontrolling the air pressures in the inflatable support pontoons. 11.The system of claim 9, wherein the inclined angle of each of the solarphotovoltaic modules is adjusted by adjusting an inflation level in oneof the inflatable upper support pontoons.
 12. A floating solarphotovoltaic array, comprising: a plurality of inflatable upper supportpontoons with upper mounting hardware thereon; a plurality of inflatablelower support pontoons with lower mounting hardware thereon; and aplurality of solar photovoltaic modules, wherein each solar photovoltaicmodule has an upper end that is connected to the mounting hardware onone of the inflatable upper support pontoons and a lower end that isconnected to the mounting hardware on one of the inflatable lowersupport pontoons, and wherein the mounting hardware on the inflatableupper support pontoons is higher than the mounting hardware on theinflatable lower support pontoons to thereby hold each of the solarphotovoltaic modules at an inclined angle.
 13. The floating solarphotovoltaic array of claim 12, further comprising: an air manifoldsystem, comprising: at least one of an air source or an air compressor,and pneumatic tubing connecting the air source or air compressor to eachof the plurality of inflatable support pontoons; pressure sensors fordetermining air pressures in the inflatable support pontoons; and an airmanifold control system for controlling the air pressures in theinflatable support pontoons.
 14. The floating solar photovoltaic arrayof claim 13, wherein the air manifold system is powered by thephotovoltaic modules in the solar photovoltaic array.
 15. The floatingsolar photovoltaic array of claim 12, wherein the inclined angle of eachof the solar photovoltaic modules is adjusted by adjusting an inflationlevel in one of the inflatable upper support pontoons.
 16. The floatingsolar photovoltaic array of claim 12, wherein the lower support pontoonshave a flattened top surface functioning as a walkway.
 17. The floatingsolar photovoltaic array of claim 12, wherein a center portion of eachsolar photovoltaic module is positioned directly above water with nomechanical structure positioned directly thereunder.
 18. The floatingsolar photovoltaic array of claim 12, further comprising: a poweredaccessory comprising at least one of an aerator, a diffuser, asub-surface agitator, a sub-surface water circulator, a sub-surfacepositioning system, a water quality sensor; a panel washer, or a birdremoval system, wherein the powered accessory is powered by thephotovoltaic modules in the solar photovoltaic array.
 19. The floatingsolar photovoltaic array of claim 18, further comprising: at least oneinverter on the array for converting DC output from the solarphotovoltaic modules into AC power, and an AC bus on the array connectedto the inverter for sending AC power to an on-shore grid, wherein thepowered accessory is connected to the AC bus.
 20. The floating solarphotovoltaic array of claim 18, further comprising: at least oneon-shore inverter for converting DC output from the solar photovoltaicmodules into AC power, and a DC bus on the array for sending DC power tothe on-shore inverter, wherein the powered accessory is connected to theDC bus.
 21. The floating solar photovoltaic array of claim 18, furthercomprising: at least one inverter that converts DC output from the solarphotovoltaic modules into AC power, wherein the powered accessory ispowered by output from the solar photovoltaic modules that has beenclipped by the at least one inverter.
 22. The floating solarphotovoltaic array of claim 18, further comprising: a battery on thearray, wherein the powered accessory is powered by the battery at timeswhen the powered accessory is not being powered by the photovoltaicmodules in the solar photovoltaic array.
 23. The floating solarphotovoltaic array of claim 12, further comprising: a plurality ofmooring cables connected to at least one of the plurality of inflatableupper support pontoons or the inflatable lower support pontoons formooring the array at a desired location on a body of water.